Question 1

In the amylase activity experiment, the development of a blue-black color upon the addition of iodine-potassium-iodide to the test tube indicates that&#10;A)the starch has been broken down.&#10;B)the starch has been denatured.&#10;C)amylase is functioning at its optimum temperature.&#10;D)the starch has not been broken down.&#10;E)glucose is present in the test tube.

Accepted Answer

The development of a blue-black color upon the addition of iodine-potassium-iodide indicates the presence of starch, meaning that the starch has not been broken down by the amylase.

Question 2

When an enzyme catalyzes a chemical reaction, it is consumed in the process, so it cannot be used repeatedly.

Accepted Answer

Enzymes are not consumed in the process of catalyzing a chemical reaction. They can be used repeatedly, as they only facilitate the reaction and are not part of the reactants or products.

Question 3

All digestive enzymes have the same optimum pH ranges.

Accepted Answer

Different digestive enzymes have different optimum pH ranges, depending on the specific type of enzyme and the nature of the substrate they act upon. For example, pepsin in the stomach has an optimum pH range of 1.5-2.0, while pancreatic enzymes like trypsin and chymotrypsin have an optimum pH range of around 7.5-8.5.

Question 4

Which digestive organ produces the enzyme maltase?&#10;A)Small intestine&#10;B)Pancreas&#10;C)Salivary glands&#10;D)Stomach&#10;E)Liver

Accepted Answer

Maltase is produced by the small intestine, specifically by the cells lining the walls of the duodenum and jejunum.

Question 5

Which of the following is not true of amylase?&#10;A)It breaks down starch into maltose.&#10;B)It is produced by more than one organ of the digestive system.&#10;C)Its optimum temperature is close to room temperature.&#10;D)The optimum pH for amylase activity is 6.8 - 7.0.&#10;E)All of these are true of amylase.

Accepted Answer

The optimum temperature range for amylase activity is between 37°C and 40°C, which is close to body temperature, but not close to room temperature. Therefore, option C is not true.

Question 6

The substance that an enzyme acts on in a chemical reaction is called its&#10;A)complex.&#10;B)product.&#10;C)modulator.&#10;D)catalyst.&#10;E)substrate.

Accepted Answer

The substance that an enzyme acts on in a chemical reaction is called its substrate. This is the molecule or molecules that bind to the active site of the enzyme and are transformed through the catalytic process. The other options are not correct because a) a complex refers to an assembly of molecules or ions, not necessarily involving an enzyme; b) a product is the result of a chemical reaction, not necessarily the substrate; c) a modulator refers to a molecule that affects the activity of an enzyme, not the substrate; and d) a catalyst is a substance that increases the rate of a chemical reaction but does not act as a substrate for the enzyme.

Question 7

In the amylase activity experiment, Benedict's solution tests for the presence of&#10;A)triglycerides.&#10;B)amino acids.&#10;C)protein.&#10;D)maltose.&#10;E)starch.

Accepted Answer

Benedict's solution is used to test for the presence of reducing sugars, such as maltose. Amylase breaks down starch into maltose, so if maltose is present in the solution after the amylase reaction, it will be detected by adding Benedict's solution and heating the solution.

Question 8

Salivary amylase is deactivated by ________ in the stomach.&#10;A)pepsinogen&#10;B)bile&#10;C)bicarbonate ions&#10;D)lipase&#10;E)hydrochloric acid

Accepted Answer

Salivary amylase, an enzyme that breaks down carbohydrates, is deactivated by the low pH produced by hydrochloric acid in the stomach, as it requires a neutral or alkaline environment to work properly.

Question 9

Enzymes can be proteins, lipids, or carbohydrates.

Accepted Answer

Enzymes are always proteins. They are biological catalysts that speed up chemical reactions within cells.

Question 10

Temperatures much higher than the optimum temperature denature enzymes, but colder temperatures do not.

Accepted Answer

Colder temperatures slow down enzyme activity but do not denature enzymes, whereas temperatures much higher than the optimum can denature enzymes, affecting their structure and function.

Question 11

Pancreatic amylase has the same action as salivary amylase.

Accepted Answer

The answer of Pancreatic amylase has the same action as...

Question 12

Which of the following is not true of enzymes?&#10;A)They are considered to be biological catalysts.&#10;B)Enzymes are relatively non-specific, and able to catalyze several chemical reactions in the body.&#10;C)Enzyme activity is temperature-dependent.&#10;D)Denaturation destroys the ability of an enzyme to function.&#10;E)All of these are true of enzymes.

Accepted Answer

The answer of Which of the following is not true...

Question 13

Denaturation does not alter the primary structure of an enzyme.

Accepted Answer

The answer of Denaturation does not alter the primary structure...

Deck 56: Action of a Digestive Enzyme